JPH0653297B2 - Aluminum plate processing method - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for processing an aluminum plate that can be suitably used for manufacturing an aluminum heat sink used in various electric and electronic devices.

Conventional technology When mounting electrical and electronic parts on an aluminum heat sink, usually,
The aluminum heat sink is provided with a recess having the same shape as the back surface shape of the electric and electronic parts. The depression is formed by placing an aluminum heat sink between a female jig having a concave portion and a male jig having a convex portion fitted into the concave portion and pressing the aluminum heat sink. The depth of the depression is typically 1/4 to 2/3 of the thickness of the aluminum heat sink.

Problems that need to be solved By the way, when pressing with a jig that has been used in the past, there was a problem that cracks often occurred in the aluminum in the recess. In order to prevent the occurrence of this crack, the present inventors first tried to provide a curved portion having a large radius of curvature at the edge of the tip of the convex portion of the male jig. Although this remedy was effective enough to prevent cracking, it created a new bend in the corners of the aluminum heatsink pit, which made it impossible to fit electrical and electronic components into the pit. There are drawbacks that cause problems.

Means for Solving the Problems The present invention forms a recess having a desired shape and depth without causing a crack in an aluminum plate and without providing a curved portion having a problematic size at a corner of the recess. We propose a method for processing aluminum plates that can be used.

That is, according to the present invention, when a concave portion (or convex portion) for mounting electric and electronic parts is formed by press working on an aluminum plate for a heat sink having a thickness of 0.3 to 5 mm, the concave portion of the female jig has a thickness of 0.2 mm or more. Mates without clearance,
A method of processing an aluminum plate, characterized in that the aluminum plate is placed and pressed between a male jig having a convex portion whose upper edge portion has a radius of curvature of 0.1 mm or less.

Effect According to the research conducted by the present inventors, when a pair of male and female jigs for forming a depression used in the related art has a large clearance at the fitting portion when the convex portion of the male jig is fitted into the concave portion of the female jig. It was found that this clearance caused cracks. On the other hand, when a pair of jigs having a clearance of 0.2 mm or less in the fitting portion between the male jig and the female jig is used, the aluminum plate is not cracked even by the press working. Further, at this time, it is not necessary to provide the above-mentioned large curved portion on the convex portion of the female jig, and as a result, a dent having a predetermined shape and depth is formed on the aluminum plate without causing a crack or a substantial curved portion at a corner. It becomes possible to do.

In the present invention, what can be subjected to pressing is an aluminum plate made of pure aluminum, various aluminum alloys, or various aluminum materials such as recycled aluminum plate. The aluminum plate may be a soft material or a hard material. In addition, those aluminum plates have easily solderable metal on one or both sides,
For example, it may have a plating layer (one layer or multiple layers) such as copper, nickel, tin, lead, or soft solder such as tinsmith solder, plan bar solder, and common solder.

The thickness of the aluminum plate before pressing (the total thickness including the plating layer when the plating layer is present) is limited to 0.3 to 5 mm. The reason is that even if it is thinner than 0.3 mm or thicker than 5 mm, the tendency that cracks occur in the portion processed by press working becomes stronger. Therefore, the preferable thickness of the aluminum plate to be processed in the present invention is 0.5 to 3 mm, especially 0.8.
~ 2 mm.

Hereinafter, the present invention will be described in detail with reference to the drawings. First
The figures show sectional views of a jig and an aluminum plate before pressing according to the present invention, wherein 1 is an aluminum plate, 2 is a female jig having a concave portion 21, and 3 is a male jig having a convex portion 31. .

L is a clearance generated when the convex portion 31 of the male jig 3 is fitted in the concave portion 21 of the female jig 2. In the present invention, L having a value of 0.2 mm or less is used. If the value of L is greater than 0.2 mm, as described above, it is necessary to provide a large R (radius of curvature) at the tip edge portion of the convex portion 31 of the male jig 3, and the adverse effect of large R is also as described above. Is.
L is preferably as small as possible, particularly preferably 0.1 mm or less, more preferably 0.05 mm or less.

In the present invention, it is not necessary to provide the leading edge R of the male jig convex portion 31, but it may be provided if it is R of 0.1 mm or less.

FIG. 2 is a sectional view of an aluminum 1'worked by the method of the present invention.

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. In the following,% means% by weight unless otherwise specified.

Example 1 A heat sink material having a copper plating layer having a thickness of 10 μm on a heat sink layer made of a hard material of pure aluminum having a thickness of 2.0 mm, and a nickel plating layer having a thickness of 10 μm on the heat sink layer was placed on the plating layer side. As shown in FIG. 1, the male jig 3 was placed between the male and female jigs and press molded at room temperature. The depth of the concave portion 21 of the jig and the height of the convex portion 31 are both 1.0 mm, and no R is formed on the tip edge of the convex portion 31. The value of the clearance 1 of the male and female jigs was 0.05 mm or less. In this example, 100 heat sinks each having the cross-sectional shape shown in FIG. 2 were produced, but the rate of occurrence of cracks in the pressed portion (defective rate) was zero.

Example 2 In place of the heat sink material used in Example 1, a thickness of 1.
5mm aluminum alloy (Al: 98%, Si: 1.0
%, Mg: 1.0%) and a heat sink material having a nickel plating layer with a thickness of 15 μm on a heat sink layer made of a hard material, press working was carried out in the same manner as in Example 1 to form 100 heat sinks. It was manufactured, but the defect rate was zero.

Comparative Example 1 Twenty heat sinks were manufactured by a method different from that of Example 1 only in that a male and female jig having a clearance 1 of 0.3 mm was used, but the defective rate was 80%.

Effect According to the present invention, it is possible to manufacture an aluminum heat sink that does not have a problematic R at the corner of the recess with a good yield.

[Brief description of drawings]

FIG. 1 is a sectional view of a jig and an aluminum plate before pressing according to the present invention, and FIG. 2 is a sectional view of an aluminum plate processed by the method of the present invention. 1: Aluminum plate 2: Female jig 21: Recess of female jig 3: Male jig 31: Convex portion of male jig L: Clearance between concave portion 21 and convex portion 31

Claims (3)

[Claims] 1. When forming a concave portion (or convex portion) on which an electric or electronic component is to be mounted by press working on an aluminum plate for a heat sink having a thickness of 0.3 to 5 mm, the concave portion of the female jig should have a diameter of 0.
Aluminum which is fitted without a clearance of 2 mm or more and is pressed by placing the above aluminum plate between a male jig and a male jig having a convex portion whose upper end edge has a radius of curvature of 0.1 mm or less. Plate processing method. 2. The method for processing an aluminum plate according to claim 1, wherein the aluminum plate has a thickness of 0.5 to 5 mm and has a plating layer of a solderable metal on one surface or both surfaces thereof. 3. The method for processing an aluminum plate according to claim 1, wherein the aluminum plate is a hard material made of pure aluminum.